The present invention relates to rotary mower cutting heads with flexible cutting heads and more particularly to improvements in the mechanism which releases the cutting blades out of the housing.
The use of rotary cutting heads has become very popular amongst professionals and domestic users, due to various reasons, such as, light weight, easy to handle, small size etc.
There are a fairly large number of such cutters and trimmers and patents which relate to improvements in these devices, such as:
U.S. Pat. Nos. 5,020,223, 4,959,904, 4,167,812, 4,151,646, 4,419,822, 4,189,833, 4,236,309, 4,412,382, 4,458,419, 4,183,138, 4,168,572, 4,145,809, 4,942,662 and 4,161,820.
As the present invention relates to the feedout mechanism of the cutting blades, which are in a form of flexible cord like flails, reference should be made to U.S. Pat. Nos. 4,203,212 and 4,259,782.
All above mentioned patents are operated in the same manner, namely the use of flails and the step wise release of same. These patents relate to different parts and improvements in such mowers, therefore all of these mowers have a sort of bump or bulge which is adapted to engage the ground while working, in order to release the predetermined length of flail. Most of the mowers have a spool on which the flails is wound and which is mounted within the housing of the mower's head. When the cutting head is bumped against the ground, said spool makes a quarter turn and release that length of flail. The main driving shaft of the mower is connected to the spool, while the rest of the housing is stationary. A spring which applies pressure on the bumper is mounted also within the housing said driving shaft is connected to an engine or an electrical motor by means of a rigid or flexible shaft.